Hi, Could you help me in this problem. "https://mirror.codeforces.com/problemsets/acmsguru/problem/99999/100".

My solution is my-submission. I'm getting WA, help me identify the mistake.

#include<iostream>
#include<fstream>
using namespace std;

int  main() {
    ifstream fin("input.in");
    ofstream fout("output.out");
    
    int a,b;
    fin>>a>>b;
    
    fout<<a + b<<"\n";
    
    return 0;
}

Thanks, pop1912